The Universe | Class 6 | Science | Chapter 16 | Maharashtra State Board
In this video, you will embark on a journey to the very beginning of the universe and learn about its formation. We will explore the formation of galaxies, including our own Milky Way, and study the various types of galaxies such as spiral, elliptical, barred spiral, and irregular. We will then delve deeper into the Milky Way galaxy and discover our own solar system, which consists of the sun and eight planets. You will gain knowledge on each of the planets, including their unique features and characteristics. Additionally, we will also discuss the role of satellites, asteroids, dwarf planets, comets, and meteors in our solar system. So, join us on this exciting journey through space and expand your knowledge of the universe. Make sure to watch till the end to discover all the wonders of our galaxy and beyond.
Questions & Answer
1. Name these.
(a) Birth place of stars.
Ans. Huge nebulae made up of dust particles and gases.
(b) Biggest planet in the solar system.
Ans. Jupiter.
(c) The galaxy which is our neighbor.
Ans. Andromeda.
(d) Brightest planet in the solar system.
Ans. Venus.
(e) Planet with largest number of satellite.
Ans. Jupiter.
(f) Planet without a single satellite.
Ans. Mercury and Venus.
(g) Planets with a rotation different from other planets.
Ans. Venus and Uranus.
(h) A celestial body that carries a tail along.
Ans. Comet.
2. Fill in the blanks.
The group of galaxies of which our Milky Way is a part is called local group.
Comets are made of frozen matter and dust particles.
The planet Uranus appears as if it is rolling along its orbit.
Jupiter is a stormy planet.
The Pole Star is the best example of a variable type of star.
3. Say if the statements given below are right or wrong. Rewrite the statements after correcting them.
(a) Venus is the planet closest to the sun.
Ans. Wrong.
C.S. Mercury is the planet closest to the sun.
(b) Mercury is called a stormy planet.
Ans. Wrong.
C.S. Jupiter is called a stormy planet.
(c) Jupiter is the biggest planet.
Ans. Right.
4. Answer the following.
(a) What is a special characteristic of the planet Mars?
Ans.
Mars is the fourth planet in our solar system.
It appears reddish as the soil on the mars contain iron. Hence it is also known as the red planet.
The highest and largest mountain in our solar system called ‘Olympus Mons’ is present on the planet Mars.
Mars has two satellites. Its rotation is in about 24 hours and it takes about 1.88 years to revolve around the sun.
(b) What are the types of galaxies?
Ans. The types of galaxies are according to their shapes. These are spiral, elliptical, barred spiral and irregular.
(c) Which celestial bodies does a galaxy include?
Ans. A galaxy includes innumerable stars and their planetary systems. It has many celestialbodies such as clusters of stars, nebulae, clouds of gases, clouds of dust, dead stars, newly born stars, etc. The Milky Way is our galaxy in which our solar system is included. It has planets, satellites, asteroids, dwarf planets and meteors.
(d) Name the different types of stars.
Ans. There is a great variety in stars. Some are very bright, some are faint. There are many colours among the stars. e.g. blue, white, yellow and reddish. Some stars have varying brightness. Their luminance changes constantly. According to these characters, the stars are of the following subtypes: Sun-Like Stars, Red Giants Stars, Super Nova, Binary or Twin Stars and Variable Stars.
(e) What are the types of comets and on what basis are they classified?
Ans. Comets are of two types.
Long period comets.
Short period comets.
This classification is based on the time taken by them to make a complete revolution around the sun. Long period comets take more than 200 years for a revolution, while short period comets take less than 200 years to make one revolution around the sun.
(f) What is the difference between meteors and meteorites?
Ans. Meteors are rocky pieces originating from the asteroid belt. Smaller rocky pieces are completely burnt due to friction with air when they enter the earth’s atmospheric layers. Meteorites are the rocky pieces that do not burn completely but fall down to the surface of the earth.
(g) What are the characteristics of the planet Neptune?
Ans.
Neptune is the eighth planet of our solar system.
One season on the Neptune planet lasts for about 41 years.
The winds blow at a very high speed on Neptune.
Neptune has 13 satellites. It takes approximately 16 hours and 11 minutes to rotate around itself and 164 years for one revolution around the sun.
4. Match the following.
Group A | Answer | Group B |
Galaxy | Spiral | From east to west |
Comet | Halley | 33 Satellites |
Sun like star | Sirius | Spiral |
Saturn | 33 Satellites | Sirius |
Venus | From east to west | Halley |
E X T R A
1. Fill in the blanks.
A group of innumerable stars and their planetary systems are together known as a Galaxy.
The Milky way is the galaxy in which our solar system is located. It is also known as Mandakini.
The galaxy that is closest to our Milky Way is called Andromeda.
It is believed that the lonar lake in Maharashtra has been formed by the impact of a meteorite.
2. Define the following.
(a) Satellite.
Ans. The celestial bodies that revolve around a planet without independently revolving around the sun are called Satellites. Moon is the natural satellite of the Earth.
(b) Asteroids.
Ans. A great number of small sized bodies could not turn into planets when the solar system was formed but continued to revolve around the sun. These bodies are known as Asteroids.
(c) Dwarf Planets.
Ans. Other smaller heavenly bodies that revolve independently around the sun in their own orbit are known as Dwarf planets.
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